easyMultiple Choice
PDE Practice Question: Stream data from a fleet of IoT devices to…
A company needs to stream data from a fleet of IoT devices to BigQuery for near-real-time analytics. The data volume is unpredictable and can spike during certain events. Which Google Cloud service should be used as the ingestion point to handle variable throughput with minimal operational overhead?
⚠ Common exam trap
Google Cloud often tests the misconception that Cloud Functions can serve as a direct ingestion point for streaming data, but candidates overlook that Cloud Functions lacks durable buffering and automatic scaling for high-throughput spikes, making Pub/Sub the correct decoupling layer.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Cloud Pub/Sub
Cloud Pub/Sub is the correct choice because it is a fully managed, scalable messaging service designed to decouple data producers from consumers, handling unpredictable and spiky throughput without requiring manual scaling. It can ingest millions of messages per second and buffer them until BigQuery is ready to consume, ensuring near-real-time analytics with minimal operational overhead.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Cloud Datastore
Why it's wrong here
Cloud Datastore is a schemaless NoSQL document database for application state, not a streaming ingestion service; it cannot absorb device event streams or load them into BigQuery. It would suit storing structured application entities. Pub/Sub is the ingestion point that buffers unpredictable throughput with minimal operational overhead.
- ✗
Cloud Functions
Why it's wrong here
Cloud Functions is compute, not an ingestion buffer; it scales per invocation and offers no durable queue to absorb unpredictable IoT spikes before BigQuery. It is tempting for lightweight event handling, but Pub/Sub is the ingestion point that decouples variable-rate publishers from BigQuery subscribers.
- ✗
Cloud Storage
Why it's wrong here
Cloud Storage is object storage for batch file landing, not a streaming ingestion endpoint; it cannot absorb unpredictable device throughput into BigQuery without added pipelines. It is tempting for cheap durable staging, but Pub/Sub is the ingestion point that buffers variable-rate streams and delivers them to BigQuery.
- ✓
Cloud Pub/Sub
Why this is correct
Cloud Pub/Sub decouples ingestion from processing, buffering unpredictable spikes automatically without provisioning capacity, which satisfies the variable-throughput and minimal-operational-overhead constraints. Its globally distributed, serverless design scales elastically per message volume, then feeds BigQuery through Dataflow, avoiding the fixed-capacity limits of alternatives such as Pub/Sub Lite or direct streaming inserts.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PDE practice question is part of Courseiva's free Google Cloud certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the PDE exam.